Katy Richards-Hrdlicka, a doctoral candidate at the Yale School of Forestry & Environmental Studies, examined 164 preserved amphibians for the presence of Batrachochytrium dendrobatidis, or Bd, an infectious pathogen driving many species to extinction. The pathogen is found on every continent inhabited by amphibians and in more than 200 species. Bd causes chytridiomycosis, which is one of the most devastating infectious diseases to vertebrate wildlife.

Richards-Hrdlicka swabbed the skin of 10 species of amphibians dating back to 1963 and preserved in formalin at the Peabody Museum of Natural History. Those swabs were then analyzed for the presence of the deadly pathogen.

"I have long proposed that the millions of amphibians maintained in natural-history collections around the world are just waiting to be sampled," she said.

The samples were then analyzed using a highly sensitive molecular test called quantitative polymerase chain reaction (qPCR) that can detect Bd DNA, even from specimens originally fixed in formalin. Formalin has long been recognized as a potent chemical that destroys DNA.